According to Kant, property applies only to touchable things, among which he includes the works of art. For the very principle of private property, a legitimate purchaser has the right to replicate and to share them without restrictions. Kant recognizes copyright only on written texts, by conceiving them as speeches that exclusively authorized spokespersons - the publishers - may convey to the public in the name of their authors. The rights of the authorized publishers, however, are justified only if they help the public to get the texts. In a Kantian environment, open source software would be worth of copyright protection, because it can be conceived as a speech meant to human beings. On the contrary, Kant would treat closed source programs as works of art, without according them copyright protection, because, as none is allowed to read and to understand them, they cannot be conceived as a speeches meant to the public. Closed source programs are like sealed books that no one is allowed to read: why do we keep on taking for granted that they are worth of copyright protection?